Method of facilitating IP connections to hosts behind middleboxes

Abstract

The present invention relates to a method and arrangement of facilitating the establishment of peer-to-peer IP connections between a public network and hosts in a private or home network. The method uses a port mapping table residing in a NAT that maps external public IP addresses and external port numbers to private IP addresses and internal port numbers. This table has so far been configured manually by a user of the private or home network. Apart from being cumbersome, it demands skills in router and network technology, skills an ordinary user of a home network often does not have. The present invention solves this problem by automatically configuring the table comprising the steps of scanning the hosts using a port scanner and detecting the internal ports in the hosts that are in an open state.

Description

TECHNICAL FIELD OF THE INVENTION[0001]The present invention relates to a method and an arrangement of facilitating the establishment of IP connections between a public network and terminals and servers in a private network behind a middlebox such as a Network Address Translator (NAT).DESCRIPTION OF RELATED ART[0002]The number of personal computers (PCs) and other terminals in each home that have access to the Internet is continuously increasing. All these terminals (forming a home / private network) are normally connected to a network access node (such as a wireless router). The network access node is in turn connected to the public network (the Internet) via a cable modem or an ADSL modem. Each terminal is allocated a private IP address that is unique within the home network. Normally, the Internet Service Provider (ISP) allocates only one public IP address per modem or network access node. So, in order to allow more than one terminal in the home network to communicate towards the in...

AI Technical Summary

Benefits of technology

[0013]With these addresses and port numbers (together called port forwarding parameters) stored in the mapping table, incoming IP connections from the public network can now easily be forwarded to the correct application in the correct host.

[0015]An advantage with the current invention is also that a user of a private / home network having no technical skills in IP communication can automatically and simply configure the network access node to receive connection establishments from the public network to a host in the private network (e.g. for receiving an incoming VoIP call).

[0016]Other advantages are that the invention saves time and that human mistakes by the user are eliminated.

Problems solved by technology

Apart from being cumbersome and error prone, it demands skills in router and network technology, skills an ordinary user of a home network often does not have.

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